Generally, in an electrolyzer tank that stores an aqueous solution, for example, city water containing, for example, common salt (sodium chloride) serving as an electrolysis aid, an electrode pair composed of an anode and a cathode is provided and a diaphragm is interposed between these electrodes. The aqueous solution is then electrolyzed under predetermined conditions to thereby produce strong acidic electrolyzed water (SAEW) on the anode side and strong alkaline electrolyzed water on the cathode side. This is called diaphragm electrolysis. It is known that the strong acidic electrolyzed water produced on the anode side contains soluble chlorine (Cl) and kills microorganisms such as various viruses and bacteria owing to the chlorine-containing hypochlorous acid (HClO), exerting a strong cleansing/sterilizing action. To describe more specifically, the strong acidic electrolyzed water exerts a sterilizing action against almost all bacteria and viruses for example, methicillin-resistant Staphylococcus aureus (MRSA) causing nosocominal infection and hepatitis B virus (HBV) and hepatitis C virus (HCV), and thus, it has been widely recognized that such a hypochlorous acid solution serves as a low-concentration high-activity sterilizing water.
Furthermore, the strong acidic electrolyzed water having such an efficacy can be easily produced just by electrolyzing, for example, a salt solution. Thus, the production cost is low. Furthermore, since irritation on the skin mucous membrane is low, the strong acidic electrolyzed water is highly safe and known to be friendly also to environment. Moreover, in the medical field, the strong acidic electrolyzed water has been approved (approval as a medical device) under the pharmaceutical laws as a product that can be used for antiseptic washing of fingers and endoscopes. The strong alkaline electrolyzed water produced on the cathode side is also said to have high cleansing performance compared to, for example, city water.
Herein, for example, Japanese Patent Laid-Open No. 2000-70947 proposes an electrolyzed water production apparatus for electrolyzing an aqueous sodium hypochlorite solution, which is produced by non-diaphragm electrolysis of a salt solution or previously prepared, used as a raw water for electrolysis.